Here, 15 people share the best marriage advice they ever received from their parents.

My grandmother, who raised me, loved to give me relationship advice. When it came to marriage, one of her favorite sayings was, "Always respect each other. Once respect is lost, it's hard to get it back."

Toni Coleman, a licensed psychotherapist and relationship coach, said that parents can make a great resource for marriage advice. "Parents have years of experience that have taught them many lessons about love," she told Business Insider.

Coleman said that many parents have learned what love is and is not, how it can change for the better or worse, and how, in marriage, it will be tested and tried in ways no one anticipates when they say "I do."

"If we're open to what our parents have to share, we could be spared a lot of grief learning it all the hard way," Coleman said.

Here, I asked 15 people for the best marriage advice they ever received from their parents. (Responses have been condensed and edited for clarity.)

1/

Allison, 31

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The advice: "It's not about getting married, it's about staying married."

2/

Tara, 42

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The best marriage advice I received from my parents was to: "Love each other as you are, not as you wish the other to be." I love that advice because the person you married will change, and you will change. But if you stay focused on the good — the essence of what you love about your spouse — you can roll with the changes and stay in love.

Rhonda, 44

My mom told me that I would often just need to let stuff go, such as comments, unintentional hurts, etc.

6/

Shlomo, 41

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Here are three lessons about relationships that I learned from my mother:

Always be loyal to your loved ones.

If you really like someone, you'll do anything to spend time with them. My mother did not believe in wishy-washy feelings. If he loves you, he'll move the moon to be with you. If she is hemming or hawing about spending time together, she probably isn't the right one.

Respect your closest family members. There's a saying that goes, "Treat your family like guests and treat your guests like family." My mother modeled the importance of respecting those closest to her — whether it meant always speaking to my father in a respectful tone or how she refrained from talking about her marriage with her friends, his honor was always sacrosanct.

7/

Eevi, 38

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The best marriage advice from my parents is: "Always answer the phone when your husband/wife is calling." My husband is an attorney and I'm a full-time entrepreneur, so this advice has served us well throughout our busy lives. Making each other a priority is the key to a loving and fulfilling marriage.

8/

Jill, 42

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The best marriage advice I ever received was from my mother — and it was the same advice her mother-in-law gave her when she married my dad: "Invest in the largest mattress you can afford."

It turns out that even though you think you want to cuddle all the time when you're first married, having room to sleep comfortably is really helpful, both in terms of getting enough sleep and also having your own space (even in bed!).

Paige, 53

My husband and I have been married for 26 years, and my parents' advice was:

Separate bathrooms — I am a slob and my husband's really neat, so I can splash water and make a mess and it does not bother him at all.

Weekly date nights — we go to the gym after work on Mondays, then grab dinner after — a fun way to start each week.

Also, at our rehearsal dinner, my father made a toast to my husband that I thought was great: "Learn to give in on the little things — it makes it easier to give in on the big things." Everyone laughed, but it really is great advice.

10/

Heidi, 44

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My dad's advice was, "Enjoy the adventure!"

11/

Brooke, 35

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As an individual, couples, and family therapist, I have a lot of insight about what makes relationships work. But the best advice my mother ever gave me was: "Don't ask who you want to be with forever, ask who you want to be with today, then the forever question answers itself." It puts too much pressure on every single move the other person makes to think about "forever," especially early on in a relationship.

The other good advice from my parents was: "Put your partner's flaws in the bigger picture rather than scrutinizing every little thing." Ask yourself if this person makes you happy overall rather than fixating on their limitations.

12/

Natalia, 50

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The best advice my late stepfather gave me was to: "Never go to bed upset with your spouse." This can extend the tension, which could last for days or weeks in some cases. Communication, no matter how difficult it may be, must be at the forefront of the marriage.

Also, my father used to say, "Once the physical attraction and the honeymoon fades away, what's left? Open communication keeps the relationship alive."

13/

Ashleigh, 38

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My parents told my husband and I to start making decisions together from the very beginning — to work as a team when it comes to every aspect of our relationship. That advice has proven to be powerful, as he and I have experienced new careers, job changes, moving to new cities, and becoming new parents.

Making decisions together shows our respect for each other, which is something we rely on when one of us has to compromise. During the times when we struggle, knowing that we are in this together helps us make our way to the other side of whatever circumstance is in front of us.

14/

Alberta, 77

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When I was single, my mother told me to marry someone who loved me more than I loved him. She thought that I had a lot of love and patience to give and felt I would be happiest with a man who showed me his love. I didn't follow her advice and married the one I had to chase. I lived with an alcoholic husband for 14 years, and he died at 45 from the disease.

One of our daughters followed the same path and died at 39 from the same alcohol and drug abuse. I still think of the man before my husband, the one I let slip through my fingers. He was in the service and used to hitchhike to get to my house in sunshine, rain, or snow. I had it all and was too young to realize it. I was looking for something that was right in front of me.

15/

Shanalee, 49

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Recently, my parents came to spend time with their grandson while my husband and I headed for the Florida Keys for some alone time. Just before leaving for the trip, with bags packed and tempers high, I told my father, "I'm leaving for Key West; I will either come back divorced or make amends."

My Irish father firmly said, "Make amends!" and slammed the door as we stood outside our home with our bags before heading to the airport. We got the point. Sometimes, it really is that simple and is truly a choice. You only need your parents to remind you.